Venting high pressure gas or steam to atmosphere during a plant or Gas Facility startup or shutdown is a common practice. These controlled releases cause dangerous noise and severe pressure drops on the vent valves. Additionally “Pigging” is a common maintenance function used in high pressure gas lines. Pigging in the context of pipelines refers to the practice of using devices known as “pigs” to perform various maintenance operations. This is done usually without stopping the flow of the product in the pipeline. These operations include but are not limited to cleaning and inspecting the pipeline. This is accomplished by inserting the pig into a “pig launcher” (or “launching station”)—an oversized section in the pipeline, reducing to the normal diameter. The launching station is then closed and the pressure-driven flow of the product in the pipeline is used to push the pig along down the pipe until it reaches the receiving trap—the “pig catcher” (or “receiving station”). Each time a “pig” is launched or retrieved, the high or low pressure gas line trap must be vented to atmosphere. Again this causes dangerous noise and stress on the release valve.
CU Services LLC, Elk Grove, Ill. makes a silencer labeled a D800. It has a flange attachment to a release pipe as shown in FIG. 1, labeled as CU 1. Release holes H vent the gas up as shown by arrow CU out. Inside the body of the CU 1 silencer are one or more circular plugs with a plurality of small vent holes. The CU 1 silencer does reduce the noise and stress on the release valve V shown in FIG. 1.
What is needed in the art is a silencer that can direct the vented gas downwind in any direction. What is also needed is a silencer that has improved noise suppression using a replenishable soft barrier wall. The new silencer also offers more portability due to its threaded connection vs. a flanged connection. The present invention meets these needs.